Immersion

A closer look at how it works

• Direct Heat Transfer: The liquid absorbs heat directly from the components (CPU, GPU, memory, etc.), eliminating the thermal resistance of air

• Heat Removal: The warmed liquid is circulated through a heat exchanger, transferring the energy to the Primary cooling loop, which is typically connected to a dry cooler or facility water system

• Types of Immersion Cooling:

  • Single-Phase: Fluid remains in liquid state; heat is carried away by pumps

  • Two-Phase: Fluid boils at low temperature, and vapor condenses on a heat exchanger, returning to liquid form

  Single phase systems are more common due to their reduced complexity, maintenance and health and safety requirements.

Below are some considerations of Immersion Cooling

Considerations

1.Fluid Selection

• Only dielectric (non-conductive) fluids designed for immersion cooling can be used

• Consider fluid type (synthetic hydrocarbons, fluorocarbons, esters) depending on performance, cost, environmental impact, and maintenance needs

• Check fluid lifetime, biodegradability, and recyclability

2.System Design

• Choose between single-phase (simpler, pump-driven circulation) and two-phase (higher efficiency, boiling-based) systems

• Ensure compatibility with existing facility infrastructure (heat exchangers, water loops, or dry coolers).

• Plan for rack density and load (immersion enables >100 kW/rack)

3. Hardware Compatibility

• Some OEM hardware may require adaptation (e.g., removing fans, replacing thermal interface materials).

• Check manufacturer warranty terms for immersion use

• Consider ease of serviceability when equipment is submerged

4. Maintenance & Operations

• Train staff on safe handling of immersion systems and fluids.

• Plan for fluid monitoring (contamination, degradation) and replacement cycles.

• Establish proper procedures for hardware installation, removal, and cleaning

5. Safety & Compliance

• Verify fire safety characteristics of chosen fluids

• Ensure compliance with environmental, ASHRAE, and local data centre regulations

• Consider spill containment and leak detection systems

6. Cost & ROI

• Initial capital investment may be higher than traditional cooling

• Long-term savings from reduced power consumption, lower cooling infrastructure costs, and extended hardware life often offset upfront costs.

• Factor in TCO rather than just CapEx